User Guide

Utilities 233
Utilities Reference
103-000153-001
August 29, 2001
Novell Confidential
Manual 99a38 July 17, 2001
The number of files kept in memory depends on the number of file cache
buffers allowed. This is determined by the amount of disk cache memory
available and the value of the Minimum File Cache Buffers parameter.
Disk cache memory not only speeds up access to file data, it is used to cache
portions of the eDirectory database. If you want to tune your NetWare server
in general, or eDirectory in particular, tune the file caching parameters. The
key to optimizing cache utilization is to monitor both Long Term Cache Hits
and LRU Sitting Time statistics. Both parameters are found in MONITOR’s
Available Options > Disk Cache Utilization. (File caching parameters can also
be set from MONITOR’s Available Options > Server Parameters.)
File caching and directory caching work together, however. In tuning the
server, directory caching and file caching need to be balanced for maximum
performance. See “How Directory Caching and File Caching Work Together”
on page 236.
Remember also that the file and directory caching parameters in SET apply
only to NetWare servers using the Traditional File System. In contrast, the
Novell
®
Storage Services
TM
(NSS
TM
) file system provides improved resource
use, requiring less memory to mount multiple volumes.
For information about NSS directory caching parameters, see “NSS Buffer
Cache Commands” on page 128 and NSS Features and Benefits.
For a description of file caching parameters, see Table 16 on page 233.
Table 16 File Caching Parameters for the Traditional File System
Parameter Use to
Read Ahead Enabled = value Specify whether the system conducts background reads to cache
in advance of blocks soon to be requested.
Supported values: ON, OFF
Default: ON
Read-aheads can happen only when sequential file accesses are
occurring.
Read Ahead LRU Sitting Time
Threshold = number
Specify the minimum cache LRU (least recently used) sitting time
for read-aheads to take place.
Supported values: 0 seconds to 1 hour
Default: 10 seconds